Perform bottom up theoretical analysis and compare
with experimental data

Use
thermodynamic ways of thinking in electronic device and material research

Coulomb
staircase is usually described in a highly mathematical way and it is not
easy to visualize it. But using the energy band method, it is possible to visualize
why the I-V characteristics are staircase-like.

The
same work has been reviewed extensively by scientists at Tales and EcolePolytechnique in Paolo Bondavalli, Pierre Legagneux,
and Didier Pribat, "Carbon nanotubes
based transistors as gas sensors: state of the art and critical review,"
Sensors and Actuators B 140 (1),
304-318 (2009) and scientists at Tales and SKKU, Didier Pribat
and Paolo Bandavalli, "Thin-Film Transistors and
Circuits Based on Carbon Nanotubes," J.
Disp. Tech. 8 (1), 54-60 (2012).
"The IBM works have been analyzed and theoretically modeled by Yamada at
NASA. Yamada has explained simple Schottky model
cannot justify alone the effect of oxygen molecules on the modulation of the Schottky values to obtain a p-type junction in air (Fig.
8)." "Yamada explains that the only way to consistently justify the
effect of oxygen is to take into an account a sort of transition between the
metal and the SWCNTs. This region is characterized
by gold clusters on the electrode surface and charged oxygen molecules."
"We can observe that in this case the Schottky
barriers for holes in air if CNTs are exposed to
air, according to the experimental results obtained by IBM researchers:
Yamada's model seems to be satisfying and suitable to describe the effective
interaction of gases on metal/SWCNT junctions."

(c) Are nanotubes unconditionally p-type? (APL 2002, NASA)

Usually
nanotubes are p-type in air. However, Fan Wu, TakuTsuneta, ReetaTarkiainen, David Gunnarsson, Tai-Hong Wang, and Pertti
J. Hakonen at Helsinki University of Technology
and Chinese Academy of Sciences wrote a paper, "Shot noise of a multiwalled carbon nanotube
field effect transistor," Phys. Rev. B 75 (12), 1 (2007) and reported the NT FET behavior at 4.2 K.

They
pointed out "Our nanotube sample is clearly
n-type doped initially [19]." They continued further "[19] The
issue of doping of carbon nanotubes appears to be
an intricate one. As argued by T. Yamada "Modeling
of Kink-shaped Carbon-nanotubeSchottky Diode with Gate Bias Modulation," in
Appl. Phys. Lett. 80, 4027 (2002) some of the early experiments can be understood
on the basis of negative doping in NTs even
though the common belief is to have positive doping either due to adsorbed
oxygen or due to a difference in metal-NT work functions." In fact,
they have observed high conductance only for Vg > 0. This means that Vg
> 0 should correspond to accumulation, and Vg < 0 depletion. Thus,
the NT must be n-type in their experiment.

Yamada
discussed the current-voltage characteristics of a gated NT metal semiconductor
junction in the literature. He showed that the Schottky
diode should be placed so that the right is a forward direction from the
Id-Vd characteristics. The rectification must
occur at the NT metal semiconductor junction. Id-Vg characteristics show
that the NT must be n-type.

3.Staircase clearly visible in dark,
but disappearing in light illumination.

4.Coulomb island
formed at a location where a pair of nanowires
fuse. The crystalline structure seems continuous there.

The staircase I-V
is considered to be due to the partial trap of an electron wave at the fused
segment. The Coulomb island there is so tiny that q2/C >> kBT and the presence or absence of a single
electron will influence transport significantly. Additionally, Rtot >> RQ so that the number
of electrons on the island is quantized. Thus, the Coulomb blockade is
considered to occur (the figure in the left column).